1. Field of the Invention
The invention relates to a rail vehicle having a concealed undercarriage, in particular a bogie, where the fairing comprises side elements that are arranged along the rail vehicle on the sides of the undercarriage and a bottom element that is arranged on the underside of the undercarriage.
The invention can be applied to bogies, in particular to internally supported bogies, where the axle bearings and the frame parts are situated between the wheels and/or the wheel discs.
2. Description of the Related Art
The running resistance of trains, particularly high-speed trains, is largely determined by the aerodynamic running resistance. A significant portion of this aerodynamic running resistance stems from the resistance of the underbody of the rail vehicle, in particular the spaces that are required for the movement of the undercarriage beneath the car bodies.
These spaces are also disadvantageous with respect to the acoustic properties of rail vehicles.
In order to bring about improvements in this regard, the normal practice is to attach aprons to the sides of the bogie of the rail vehicle.
Moreover, WO 2010/086201 A1 discloses a design of the fairing in the form of a peripheral wall for surrounding the bogie, and a fastening device for rotationally guiding the peripheral wall at its upper edge on a car body of the rail vehicle, such that the rotation of the peripheral wall corresponds to the rotation of the bogie in each case. The fairing is covered at the lower edge of the peripheral wall by an underbody-like terminating part, which has fasteners for its attachment to the bogie. Here, the aprons are therefore formed rotatable relative to the car body, and the underbody-like terminating part is likewise connected to the axle bearings or bogie frame.
WO 2012/069269 A1 also discloses a rail vehicle having a concealed undercarriage, where the lateral fairing elements follow the movement of the bogie and in conjunction with a bottom element provide an integral complete fairing of the bogie.
The conventional aprons that are attached to the sides of the bogie of the rail vehicle ignore the aerodynamic properties of the underside of the undercarriage. The rotatable lateral fairing elements and likewise rotatable bottom element involve a sophisticated suspension of the lateral fairing elements and reduce the running stability due to their comparatively high moment of inertia about the vertical axis of the undercarriage.